The use of uninterruptible power supplies (UPSs) having battery back-up systems to provide regulated, uninterrupted power for sensitive and/or critical loads, such as computer systems, and other data processing systems is well known.
Uninterruptible power supplies are used to protect sensitive electronic equipment against disturbances which can occasionally appear on the public electricity supply network. These disturbances can vary from voltage changes of very short duration to total loss of supply for a considerable period, resulting in the loss of computer data and, in some instances, actual damage to electrical equipment.
In addition, there are a multiplicity of electronic devices that might benefit from an uninterruptible power supply that includes power surge protection. These devices include computers and computer peripherals that are often co-located in a small area. When a UPS is used with a computer and its associated peripherals, because of the small area generally available for power cables and signal cables, the cables often times form a “rat's nest” of bunching and bending cables which over time compromise the integrity of the cables.
The operation of a UPS is generally well known, and FIG. 1 shows a typical prior art UPS 10 used to provide regulated uninterrupted power. The UPS 10 includes an input filter/surge protector 12, a transfer switch 14, a controller 16, a battery 18, a battery charger 19, an inverter 20, and a DC-DC converter 23. The UPS also includes an input 24 for coupling to an AC power source and an outlet 26 for coupling to a load.
The UPS 10 operates as follows. The filter/surge protector 12 receives input AC power from the AC power source through the input 24, filters the input AC power and provides filtered AC power to the transfer switch and the battery charger. The transfer switch 14 receives the AC power from the filter/surge protector 12 and also receives AC power from the inverter 20. The controller 16 determines whether the AC power available from the filter/surge protector is within predetermined tolerances, and if so, controls the transfer switch to provide the AC power from the filter/surge protector to the outlet 26. If the AC power from the rectifier is not within the predetermined tolerances, which may occur because of “brown out,” “high line,” or “black out” conditions, or due to power surges, then the controller controls the transfer switch to provide the AC power from the inverter 20. The DC-DC converter 23 is an optional component that converts the output of the battery to a voltage that is compatible with the inverter. Depending on the particular inverter and battery used the inverter may be operatively coupled to the battery either directly or through a DC-DC converter.
The inverter 20 of the prior art UPS 10 receives DC power from the DC-DC converter 23, converts the DC voltage to AC voltage, and regulates the AC voltage to predetermined specifications. The inverter 20 provides the regulated AC voltage to the transfer switch. Depending on the capacity of the battery and the power requirements of the load, the UPS 10 can provide power to the load during brief power source “dropouts” or for extended power outages.
A major drawback of typical prior art uninterruptible power supplies is that the positioning of electrical outlets in these supplies is typically on the top or back surface of the supply and is generally difficult to plug in power cords from a plurality of electronic components without producing cable bunching and bending.
Portable distribution boxes having an angled surface area dedicated to providing electrical contact are known. One example of a portable distribution box is described in U.S. Pat. No. 2,988,655. However, these prior art portable distribution boxes typically do not provide power surge protection nor do they provide back-up power that may facilitate a gradual shut down of electrical devices connected to the portable distribution box.